A novel, relatively inexpensive and accurate flow cytometric technique, which identifies and quantitates the number of peripheral blood mononuclear cells (PBMC) infected with the human immunodeficiency virus (HIV), will be used to monitor the effect of antiviral therapies such as Zidovudine (AZT), dideoxycytidine (ddC), and dideoxyinosine (ddi) on the number of HIV- infected cells in AIDS patients undergoing these treatments. In addition, the effects of these antiviral compounds on the amount of free virus in the circulation will be measured using the p24 antigen-capture enzyme-linked immunosorbant assay (ELISA). We expect to be able to measure a decrease in the amount of HIV in the mononuclear cells using the flow cytometric technique and a decrease in the amount of free virus in the plasma using the p24 antigen-capture ELISA technique. These studies comparing the ability of these two techniques to measure the amount of virus in the circulation of AIDS patients undergoing chemotherapy for their disease should lead to useful and meaningful assays for monitoring the effect of antiviral therapies on the amount of cell-associated and cell-free HIV in these patients. Any decreases in the amount of HIV in the circulation will be correlated with the improvement in clinical status of the patient and other markers of improvement in these HIV-infected patients.